Google widened lead in search in December

Google expanded its usage share in the U.S. search-engine market last month when it handled a whopping 72.1 percent of all queries, up from 65.9 percent in December 2007, Hitwise said Monday.

The other three main search engines all lost share. Yahoo came in a very distant second with 17.8 percent, down from 20.9 percent in December 2007. Microsoft was third with 5.6 percent, down from 7 percent, while Ask.com ranked fourth with 3.4 percent, down from 4.1 percent.

For the entire year, Google nabbed 69.5 percent of all U.S. search queries, followed by Yahoo with 19.2 percent, Microsoft with almost 5.9 percent and Ask.com with 3.2 percent.

Google's unparalleled popularity among search-engine users translates directly into a dominant position in search advertising, the largest segment of online advertising.

According to an IDC study published in December, search advertising accounted for 51 percent of all U.S. online advertising spending in 2008's third quarter. Google nabbed 54 percent of search-ad spending in the third quarter in the U.S., followed by Yahoo with 12.6 percent, according to IDC.

Google finished the third quarter with a 35 percent share of total U.S. online ad spending, followed by Yahoo with 14 percent, according to IDC.